1. Field of the Invention
The present invention relates to a protection structure, especially a protection structure that is applicable to micro-electro-mechanical system (MEMS) and corresponding pads.
2. Description of the Prior Art
Along with the development of technology and the improvement of the semiconductor techniques, electronic devices are widely used in modern life. Micro-electro-mechanical system (MEMS) technology is to fabricate micro mechanical devices by using conventional semiconductor technologies such as electroplating, etching such that a mechanical component in a micro-meter scale may be formed. The MEMS device may be, for example, the voltage controlling component in an ink printer, the gyroscope in a car to detect the tilt of the car, or the vibration membrane in a microphone to sense a sound. The MEMS technology which combines the fabrication process of the mechanical and the electronic devices has the advantages of low cost, high performance and high density.
At present, the MEMS is usually integrated into a chip in a form of system on chip (SOC), especially a chip fabricated by a conventional CMOS process. For instance, a MEMS region and a CMOS region may be formed on a die simultaneously. In the present fabrication method to integrate the CMOS region and the MEMS region, many problems may occur. For example, when fabricating the CMOS and the MEMS devices, the influence of fabrication methods between each region and the usage interference of the product should be avoided, making it a serious problem that needs to be studied and overcome.